Treatment by compression of fibrocement wet sheet material and the like



Feb. 21, 1961 A. F. H. J. M. NUYENS 2,972,378

TREATMENT BY COMPRESSION 0F FIBRO-CEMENT WET SHEET MATERIAL AND THE LIKE4 Sheets-Sheet 1 Filed June 20, 1956 531, 1951 A. F. H. J. M. NUYENS2,972,378

I TREATMENT BY COMPRESSION OF FIBRO-CEMENT wET SHEET MATERIAL AND THELIKE Filed June 20, 1956 4 Sheets-Sheet 2 ,Feb. 21, 1 A. F. H. J. M.NUYENS 2,972,373

TREATMENT BY COMPRESSION OF FIBROCEMENT WET SHEET MATERIAL AND THE LIKE4 Sheets-Sheet 5 Filed June 20, 1956 F. H. J. M. NUYENS TREATMENT BYCOMPRESSION OF FIBRO-CEMENT WET SHEET MATERIAL AND THE LIKE Feb. 21,1961 4 Sheets-Sheet 4 Filed June 20, 1956 TREATMENT BY COMPRESSION OFFIBRO- CEKREENT WET SHEET MATERIAL AND THE LI Augustinus FranciscusHenricus Josephus Maria Nuyeus, '162 Ave. de Merode, Turnhout, BelgiumMy invention relates to apparatus for treating, by compression, thefibrous wet sheet material produced by pulp gathering or wet machines ofthe Hatcheck or Fourdrinier type as used in the manufacturing ofasbestos-cement or fibro-cement products, paper card'or mill-board andthe like.

Generally speaking, this apparatus can be applied in a terminaloperation following the one performed by the wet machine or even duringthe formulation of the sheet on the accumulator cylinder of thismachine.

An object of my invention is to provide continuity in the operations andto eliminate the expensive, slow working and very cumbersome statichydraulic presses as well as some of the costly conventional dehydratingprocesses.

The principal object, however, is to improve substantially the qualityof the products, not only by squeezing out, under a tremenduouspressure, the free water and the air retained in the sheet and thusrendering the ma terial considerably more dense, but alsothroughlamination, stressing its'fiber structure, and so forth.

The compression, with calenders, of wet fibrous sheets or layers of wetfibrous material has always been a problem, the compression depending onthe relationship of different factors such as: the pressure applied andits duration the diameter of the cylinders aswell as the hardness of thecontact faces, the rotating speed of the cylinders and sine qua noncondition, the ability of the fluids, imprisoned in the material, tomigrate.

The calender of the invention is equipped, in principle, with twosuperposed work cylinders maintained at the required spacing by means ofset screws and powerful hydraulic buffers and between which the wetsheet, formerly produced by the wet machine, is progressively subjectedto a slowly increasing linear pressure or lamination. In order to allowthe fluids imprisoned in the material to migrate, which isessential, thelower cylinder is provided on its surface, with a multitude of dulyspaced grooves, and is covered by a. hard and easilyremovable elementsuch as a perforated sheet metal which has a filtering function. a

The fluids forced through the perforations migrat freely in the grooves,which constitute a drain. In order to accelerate the flow of the waterin the grooves, the center line of the two cylinders is at approx. 15from vertical.

Fibrous wet sheets produced by pulp gathering or wet machines andpassing subsequently between-those two slowly revolving cylinders areprogressively compressed, strained and stretched. They will thus betransformed into dehydrated rigid mats, extremely dense andoutstandingly tough.

This remarkable toughness results from the milling.

action which laminates the material and stretches the fibres. Thesefibres are thus put under a stress which tates Patent Fig. 3 illustratesin broken away section a detail of a roller of the press of Figs. 1 and2;

Figs. 4-7 show further details; I

Figs. 8 and 9 relate to a special embodiment in which, the wet machineis employed for the production of sheets bearing relief drawings on oneside.

In the treatment according to Figs. 1 and 2, which relate to thesubsequent treatment of the sheet delivered by the wet machine, thecalender is composed of the tw Work cylinders 1 and 2 of large diameterand with a.

circumference larger than the full length of the sheet to be treated. 1

The frame of the structure includes beams 3 connected and spaced bybolts 5. i

At the top of the beams are movable heads 6 attached to the beam 3 bybolts 9.

In each head 6 which is supplied with oil'under pressure moves a piston10 which acts as a hydraulic buffer and reacts. on the bearing 11 of theupper cylinder 1.

Beneath each bearing 11 a 'set screw'12 engages in a cross-beam 13 whichrests by means of superposed vertical members at the bottom of the slide15 of the beam.

Screw 12, provided at its lower end with a locknut,

acts as a set screw to avoid close contact between cylinders 1 and 2 ortheir covers, which contact could damage them.

The lower cylinder 2 is driven by a variable speed reducer motor (notshown), acting by means of a pinion on a gear 17, thus driving thiscylinder at'a speed,-

for example, of 6 to 1.0 feet per minute corresponding to the averageoutput of a normal wet machine. I

Grooves 20 spaced at 0.055 inch, for instance, by crests 21' (Figs. 3-6)are provided on the circumference of the lower cylinder 2, concentricwith the axis thereof. 7

This cylinder 2 is covered by a removable sheet metal 21 provided withperforations 22, the diameter of which is larger (0.075"inch, forexample) than'the width of the crests '21 in such a way that each of theperforations 22 always communicates with one or two grooves 20 whateverthe position of the sheet metal may be on cylinder 2.

The removable sheet metal 21 must be free to elon-,

pivoting on a cam (not shown).

The lower cylinder 2 which is inder. The lower cylinder provides,moreoverjtor the straining of the sheet.

Patented vFeb. 21, 1961 Rod, 24 is retained at each end projectingbeyond the cylinder by a through bolt.

7 the driving cylinder; drives the fibrous sheet which becomes squeezedbe-f tween the two cylinders and thus drivesthe upper cyl The uppercylinder can also be covered by an easily removed element such as asheet of metal or any suitable lining, which is provided with whateverrelief drawings may be desired, but this cylinder is not provided withperforations as is the lower cylinder. This lining will be attached inthe same way as the perforated sheet metal covering the lower cylinder.

The upper cylinder 1 provides then for the impression of the surface ofthe sheet, impressions which are effected at the same time as thecompression.

The upper cylinder may also be smooth, the lower cylinder being coveredas above by a hard and removablefiltering element.

The two cylinders can be provided with corrugations, the lower cylinderbeing grooved and covered by a removable filter element also corrugated.

In this way, there are various alternatives as follows:

(a) The lower cylinder is covered. The upper cylinder is not covered(smooth).

(b) The two cylinders are covered.

(c) The lower cylinder, which is corrugated, is covered. The uppercylinder, which is corrugated, is not covered.

In these three alternatives, the pressure may be exerted on one or theother cylinder, according to the planning of the machine.

A removable spray pipe 80 can be provided which will prevent clogging upof the perforations of the removable element.

As shown in Fig. 7, gears 33 and 34, connected by means of a chain 35are mounted on the ends of the shafts 30 and 31 of the cylinders 1 and2. These shafts are located in bearings 11 and 32. The chain 35 ismounted such as to invert rotation and passes around a guiding wheel 36and is stressed by means of a lever 37 provided with a counter weight38.

Lever 37 rests on an adjustable support 39 or hydraulic shock absorber.

The main function of this device is to bring both cylinders back totheir initial positions, with the joints of the respective liningsfacing each other, after passage of each sheet which impulses the uppercylinder. By starting from another position, the sheets would be markedby the joints.

Since the thickness of a lining increases the circumference of the uppercylinder, the rotation of this cylinder will be slower than the lowercylinder. Therefore, the chain 35 will loosen in section 46 directlyconmeeting the two gears 33 and 34. On the other hand, the lever 37 Willmove upwards.

At the time the treated sheet comes from between the cylinders, theupper cylinder, by the action of the counter weight 38 will be timedagain with the lower cylinder.

Figure 8 shows an application of the calender of a wet machine (Hatcheckprocess) intended for the manufacturing of fibro-cement productscomposed of fibres and hydraulic binders.

According to this well known process, one or more layers of an aqueousslurry of fibers and hydraulic binders are conveyed by an endless feltbetween the two cylinders of this calender.

These thin layers accumulate a number of times on the upper cylinderuntil a laminated material of the desired thickness has been obtainedwhich is then slitted lengthwise of this cylinder and removed therefrom.

In accordance with the invention, a similar machine is used composed oftwo cylinders 41 and 42 of unequal diameter, the upper cylinder havingthe largest diameter and having a circumference corresponding with thetheoretical length of the sheet.

The functions of the lower cylinder 42 are as follows:

(a) To support and drive the conveying felt 43 carrying the thin layerof wet fibrous material and which is guided by rollers 44 and 45. One ofthese rollers is located in such a way that the felt 43 contacts a partof the circumference of cylinder 41. The felt drives the upper cylinder.

(b) To contribute to the straining of the felt and of the depot of thefibrous material adhering to the upper cylinder.

This upper cylinder 41 is covered by a removable element 46, forinstance sheet metal or any suitable lining of which the length isslightly less than the circumference of the cylinder.

To this element, a rod 48 is attached, for instance by screws 47, therod being located in the cylinder 41 and being wedged therein by meansof a conical key (not shown). This rod 48 has, at a place where it isnot covered by the movable element 46, a groove 49, the purpose of'which will be explained further on.

The functions of the upper cylinder are as follows:

(A) To gather at each rotation the thin layer of material carried byfelt 43. At each rotation, a layer will be superposed on the precedinglayers to form finally a fibrous sheet by these subsequent additions.

(B) To exert, by means of gravity a slight pres sure on the conveyingfelt 43 which thus is strained as well as the material. This pressurealso ascertains the integration of the superposed layers of material onthe cylinder.

As a result of the invention, the slight pressure exerted at eachrotation of the upper cylinder on a part of the layers already gatheredis used to produce an embossing which is effected on the plasticmaterial from the very moment of its formulation.

This modeling is obtained by means of cover or lining 46 carrying apattern in negative relief corresponding to the one which must beobtained on the sheet.

When the desired number of layers is reached, the fibrous sheet isremoved from cylinder 41 through a cutting operation by means of a toolintroduced in groove 49.

It is clear that the advantage obtained is that only one die plate mustbe provided for each pattern to be executed whereas heretofore anengraved cylinder was required for each different design.

In this way the use of a machine is extended simply by removal of a die46 and its replacement by another one having another design.

The position of roller 44 can be adjusted by means of a screw 50provided with a handwheel 51 and acting on an iron 52 provided at itsend with a fork 53 supporting the shaft 54 on the roller 44.

The shaft 55 of cylinder 41 is located in a movable bearing 56 andattached to the same by a screw 57 or by another device.

A sleeve 58 is provided around bearing '56 in which sleeve a groove 59allows the passage of shaft 55 when a cylinder 41 must be replaced byanother one.

A pressure is exerted on sleeve 58 by a screw rod 60 engaging in amember 61 allowing an adjustment of the length; this rod is providedwith a handwheel 62 and goes through a stationary sleeve 63 onsupporting column 64.

A certain pressure can be exerted on felt 43 by means of a counterweight65 mounted on lever 66 articulated at 67 on the frame 68; on this lever66 an arm 69 of adjustable length extending upwards is pivoted and arm69 is attached at its upper end to an arm 70 articulated at 71 to column64.

What is claimed is:

1. Apparatus comprising a source of fibro-cement sheet, superposedcylinders adjacent said source the lowermost of which is provided withperipheral grooves concentric with the axis of the lowermost cylinder,means adjustably supporting the cylinders to accommodate the sheettherebetween, means operatively cou pled to and driving the lower of thecylinders and,

through the intermediary of said sheet, the upper of the cylinders, anda perforated cover on the lower roller having perforations incommunication with said grooves.

2. Apparatus as claimed in claim 1 comprising gears on said cylindersand rotatable therewith, a lever, means fixed relative to said cylindersand pivotallysupporting said lever, a pulley on said lever, an endlesschain engaging said gears and pulley, and a weight on the lever wherebythe cylinders are maintained in predetermined registration when idle.

3. Apparatus as claimed in claim 1, wherein said cover is a cylindricalsheet having adjacent ends and the lowermost cylinder is provided withan axially disposed dovetail peripheral groove and with a second grooveparallel to but spaced from the first said groove, comprising a rodconnected to said cover at one end thereof and accommodated within saiddovetail groove, a wedge in said dovetail groove for locking the rodtherein, and a second rod displaceable in said second groove andconnected with said cover at the other end thereof whereby said ends arefreely displaceable relative to one another.

References Cited in the file of this patent UNITED STATES PATENTS ThomMar. 15, Hofmeir Dec. 13, Sinclair May 25, Tveden July 15, Haug May 13,Lorenz Apr. 27, Doerr Oct. 11, MacLachlan Oct. 11, MacMenigall June 11,Boyer June 14, Kane June 6, Hornbostel Feb. 25, Cavagnaro Aug. 18,Ireland et a1. Feb. 2, Schmitz Jan. 12, Walter Apr. 27, Wood July 20,Zesbaugh June 28,

Cohn ct a1. Jan. 3,

